The present invention pertains to a method for measuring forces produced by a tire at high speed.
The measuring of tires were initially for radial and lateral run-out, however with the advent of better highways and higher speeds it was necessary to measure more of the dynamically induced force variations which were generated by the tire itself. The force variations are attributable to one or more factors in the tire such as splice variations or irregularities, variations of dimensions in the materials, irregularities in the fabric construction as in calendaring or construction of breakers, belts or cutting and splicing of fabric material as well as other deviations that are introduced into a tire due to mechanical imperfection such as inherent in the tire building machines as well as human inaccuracies.
The means used in making these measurements includes a wheel and axle assembly on which the tire to be tested is mounted. A rotating load wheel is applied against the test tire at a predetermined loading and as the tire is rotated, the variations in the forces are recorded, indicating the amount of variation in force the tire exerts on the load wheel.
The present invention overcomes many disadvantages of the past force variance measuring machine, providing a rapid and accurate means for measuring forces at high speed running on a road wheel or loadwheel wherein the imbalanced forces are separated and removed from the radial force variance that is measured at the axle of the tire being tested to give a final contact or road surface forces which may be recorded. Such operation may be performed automatically without stopping the operation.